distinguish barcode's input with keyboard's input

Hi there, please help me, is there any way to distinguish between barcode's scanner input with the keyboard's input?

When you ask a question, please consider the person on the other end who'll be trying to answer it. In particular, it's important to know whether the person on the other end knows what system you are asking about. I, for one, have no clue what you are looking at in asking your question, so I have no context from which to answer it.

Your question is similar to me asking you "is the wire suitable?" See? You have no idea. True, you could know the answer, but unless I, first, tell you how the wire is being used and, therefore, give you a context from which to answer, you have no idea.

True, I could've just ignored your question leaving you to wonder why no one was answering it, but I figured I'd say something such that you, at least, could get an answer.

Added after 19 minutes:


It would seem to me that you are asking the question

"Can a keyboard's output be differentiated from a barcode scanner's output?"

In other words, if the two outputs were compared, does one differ from the other in a way that is detectable?

My first question is what keyboard? Does the keyboard have a parallel or a serial output? I'd guess it's serial or the answer would be obvious. Next, I'd ask, when you press a key, what comes out? How many bits make up a character? What size is the barcode? Is the barcode scanned at a fixed rate, or will the rate vary? If the rate varies, then how do you know when one number begins and ends? The keyboard's output will be clocked at a fixed bit rate that should never vary. Hence, that fact may get you somewhere in differentiating a keyboard's output from a barcode scanner's.

This is all assuming I actually understood your question in the first place. ;-)

Hi Euler's Identity, thank you for your reply and thanks for your correction i am sorry because of my bad english grammar.

Yes, you got my question. I wanted to ask if I connect a barcode scanner and a keyboard to the PS/2 of the PC. If there is an input from one of those two devices to the PC, from which input device does it come from? It is come from keyboard? or it is come from barcode scanner? how to distinguish it?

My first question is what keyboard? Does the keyboard have a parallel or a serial output? I'd guess it's serial or the answer would be obvious. Next, I'd ask, when you press a key, what comes out? How many bits make up a character? What size is the barcode? Is the barcode scanned at a fixed rate, or will the rate vary? If the rate varies, then how do you know when one number begins and ends? The keyboard's output will be clocked at a fixed bit rate that should never vary. Hence, that fact may get you somewhere in differentiating a keyboard's output from a barcode scanner's.

Click to expand...

Regarding your questions as quoted above, I cannot answer all of them because of my limitation, hope you would kindly help to give me a brief explanation about this case. I am not sure how many bits make up a character, is it 16bits? 1 byte for the ASCII code, and 1 byte for attribute? I am also not sure about the barcode scanner's scanning rate. How to differentiating a barcode scanner's output from a keyboard's?

I am sorry with my poor on using english language, just give me correction on my grammar if there are any mistakes on it. Thank you

Hi,

This depends on the reader and barcode type, an example:

I've experienced to read 3of9 barcodes with PS2; 3of9 barcode contents starts and ends with the '*' char: so if we receive a stream of data delimited with '*' within a certain amount of time, we assume this content is coming from a reader and not from the keyboard.

HH

NeuralC